Performance test of a high precise accelerometer or an inertial sensor on the ground is inevitably limited by the seismic noise. A torsion pendulum has been used to investigate the performances of an electrostatic acc...Performance test of a high precise accelerometer or an inertial sensor on the ground is inevitably limited by the seismic noise. A torsion pendulum has been used to investigate the performances of an electrostatic accelerometer, where the test mass is suspended by a fiber to compensate for its weight, and this scheme demonstrates an advantage, compared with the high-voltage levitation scheme, in which the effect of the seismic noise can be suppressed for a few orders of magnitude in low frequencies. In this work, the capacitive electrode cage is proposed to be suspended by another pendulum, and theoretical analysis shows that the effects of the seismic noise can be further suppressed for more than one order by suspending the electrode cage.展开更多
The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random t...The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random telegraph signal noise in the pixel source follower based on the binomial distribution is set up. The number of electrons captured or released by the oxide traps in the unit time is described as the random variables which obey the binomial distribution. As a result,the output states and the corresponding probabilities of the first and the second samples of the correlated double sampling circuit are acquired. The standard deviation of the output states after the correlated double sampling circuit can be obtained accordingly. In the simulation section, one hundred thousand samples of the source follower MOSFET have been simulated,and the simulation results show that the proposed model has the similar statistical characteristics with the existing models under the effect of the channel length and the density of the oxide trap. Moreover, the noise histogram of the proposed model has been evaluated at different environmental temperatures.展开更多
Radiation effects on complementary metal-oxide-semiconductor（CMOS） active pixel sensors（APS） induced by proton and γ-ray are presented. The samples are manufactured with the standards of 0.35 μm CMOS technology....Radiation effects on complementary metal-oxide-semiconductor（CMOS） active pixel sensors（APS） induced by proton and γ-ray are presented. The samples are manufactured with the standards of 0.35 μm CMOS technology. Two samples have been irradiated un-biased by 23 MeV protons with fluences of 1.43 × 10^11 protons/cm^2 and 2.14 × 10^11 protons/cm-2,respectively, while another sample has been exposed un-biased to 65 krad（Si） ^60Co γ-ray. The influences of radiation on the dark current, fixed-pattern noise under illumination, quantum efficiency, and conversion gain of the samples are investigated. The dark current, which increases drastically, is obtained by the theory based on thermal generation and the trap induced upon the irradiation. Both γ-ray and proton irradiation increase the non-uniformity of the signal, but the nonuniformity induced by protons is even worse. The degradation mechanisms of CMOS APS image sensors are analyzed,especially for the interaction induced by proton displacement damage and total ion dose（TID） damage.展开更多
Unknown dynamics including mismatched mechanical dynamics(i.e.,parametric uncertainties,unmodeled friction and external disturbances)and matched actuator dynamics(i.e.,pressure and flow characteristic uncertainties)br...Unknown dynamics including mismatched mechanical dynamics(i.e.,parametric uncertainties,unmodeled friction and external disturbances)and matched actuator dynamics(i.e.,pressure and flow characteristic uncertainties)broadly exist in hydraulic actuation systems(HASs),which can hinder the achievement of high-precision motion axis control.To surmount the practical issue,an observer-based control framework with a simple structure and low computation is developed for HASs.First,a simple observer is utilized to estimate mismatched and matched unknown dynamics for feedforward compensation.Then combining the backstepping design and adaptive control,an appropriate observer-based composite controller is provided,in which nonlinear feedback terms with updated gains are adopted to further improve the tracking accuracy.Moreover,a smooth nonlinear filter is introduced to shun the“explosion of complexity”and attenuate the impact of sensor noise on control performance.As a result,this synthesized controller is more suitable for practical use.Stability analysis uncovers that the developed controller assures the asymptotic convergence of the tracking error.The merits of the proposed approach are validated via comparative experiment results applied in an HAS with an inertial load as well.展开更多
Sensors are a crucial component in heating,ventilation,and air conditioning(HVAC)control systems,and the quality of them plays an important role in control accuracy.In the research of fault detection and control optim...Sensors are a crucial component in heating,ventilation,and air conditioning(HVAC)control systems,and the quality of them plays an important role in control accuracy.In the research of fault detection and control optimization,improving sensor data quality has inspiring potential in application.It has been largely limited to the application of signal processing methods in research focus,whereas a detailed analysis of the characteristics of signals from various sensors of the HVAC system has not been conducted.Therefore,this study analyzes the time-frequency domain characteristics of control sensors within HVAC systems through integrating the structural design and control logic of such systems.Additionally,the research examines the correlations between control sensors in HVAC systems.Based on statistical principles and the energy-mass dynamic laws of the equipment,this paper defines first-class(Ⅰ)correlated sensors and second-class(Ⅱ)correlated sensors.To sum up,the main contribution of this paper is conducting a fundamental study on the characteristics of control sensors within HVAC systems,providing theoretical reference for future research on HVAC system fault diagnosis and control optimization.展开更多
The capability of ADRC is studied for linear time-invariant SISO minimum-phase systems with unknown orders, uncertain relative degrees, and unknown input disturbances. It is proved that ADRC can reject the unknown inp...The capability of ADRC is studied for linear time-invariant SISO minimum-phase systems with unknown orders, uncertain relative degrees, and unknown input disturbances. It is proved that ADRC can reject the unknown input disturbance and guarantee the close-loop stability for the plants with unknown but bounded relative degrees. Meanwhile, some close-loop performances can be achieved. The influence of the sensor noise is also discussed. And it is demonstrated by numerical examples that one ADRC with fixed parameters can be applied to a group of plants of different orders, relative degrees, and parameters.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11235004
文摘Performance test of a high precise accelerometer or an inertial sensor on the ground is inevitably limited by the seismic noise. A torsion pendulum has been used to investigate the performances of an electrostatic accelerometer, where the test mass is suspended by a fiber to compensate for its weight, and this scheme demonstrates an advantage, compared with the high-voltage levitation scheme, in which the effect of the seismic noise can be suppressed for a few orders of magnitude in low frequencies. In this work, the capacitive electrode cage is proposed to be suspended by another pendulum, and theoretical analysis shows that the effects of the seismic noise can be further suppressed for more than one order by suspending the electrode cage.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61372156 and 61405053)the Natural Science Foundation of Zhejiang Province of China(Grant No.LZ13F04001)
文摘The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random telegraph signal noise in the pixel source follower based on the binomial distribution is set up. The number of electrons captured or released by the oxide traps in the unit time is described as the random variables which obey the binomial distribution. As a result,the output states and the corresponding probabilities of the first and the second samples of the correlated double sampling circuit are acquired. The standard deviation of the output states after the correlated double sampling circuit can be obtained accordingly. In the simulation section, one hundred thousand samples of the source follower MOSFET have been simulated,and the simulation results show that the proposed model has the similar statistical characteristics with the existing models under the effect of the channel length and the density of the oxide trap. Moreover, the noise histogram of the proposed model has been evaluated at different environmental temperatures.
基金Project supported the National Natural Science Foundation of China(Grant No.11675259)the West Light Foundation of the Chinese Academy of Sciences(Grant Nos.XBBS201316,2016-QNXZ-B-2,and 2016-QNXZ-B-8)Young Talent Training Project of Science and Technology,Xinjiang,China(Grant No.qn2015yx035)
文摘Radiation effects on complementary metal-oxide-semiconductor（CMOS） active pixel sensors（APS） induced by proton and γ-ray are presented. The samples are manufactured with the standards of 0.35 μm CMOS technology. Two samples have been irradiated un-biased by 23 MeV protons with fluences of 1.43 × 10^11 protons/cm^2 and 2.14 × 10^11 protons/cm-2,respectively, while another sample has been exposed un-biased to 65 krad（Si） ^60Co γ-ray. The influences of radiation on the dark current, fixed-pattern noise under illumination, quantum efficiency, and conversion gain of the samples are investigated. The dark current, which increases drastically, is obtained by the theory based on thermal generation and the trap induced upon the irradiation. Both γ-ray and proton irradiation increase the non-uniformity of the signal, but the nonuniformity induced by protons is even worse. The degradation mechanisms of CMOS APS image sensors are analyzed,especially for the interaction induced by proton displacement damage and total ion dose（TID） damage.
基金This work was supported in part by the National Key R&D Program of China(No.2021YFB2011300)the National Natural Science Foundation of China(No.52075262,51905271,52275062)+1 种基金the Fok Ying-Tong Education Foundation of China(No.171044)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_0471).
文摘Unknown dynamics including mismatched mechanical dynamics(i.e.,parametric uncertainties,unmodeled friction and external disturbances)and matched actuator dynamics(i.e.,pressure and flow characteristic uncertainties)broadly exist in hydraulic actuation systems(HASs),which can hinder the achievement of high-precision motion axis control.To surmount the practical issue,an observer-based control framework with a simple structure and low computation is developed for HASs.First,a simple observer is utilized to estimate mismatched and matched unknown dynamics for feedforward compensation.Then combining the backstepping design and adaptive control,an appropriate observer-based composite controller is provided,in which nonlinear feedback terms with updated gains are adopted to further improve the tracking accuracy.Moreover,a smooth nonlinear filter is introduced to shun the“explosion of complexity”and attenuate the impact of sensor noise on control performance.As a result,this synthesized controller is more suitable for practical use.Stability analysis uncovers that the developed controller assures the asymptotic convergence of the tracking error.The merits of the proposed approach are validated via comparative experiment results applied in an HAS with an inertial load as well.
基金supported by the National Natural Science Foundation of China(Grant Nos.52478080,52408101,and 52078096)the Natural Science Foundation Joint Fund of Liaoning Province(Grant No.2023-MSBA-023)+2 种基金2023 Dalian University of Technology-Cardiff University Cooperation and Exchange Foundation Project2023 International Exchange Foundation Project of“Co-Creation of Excellence Program”from Dalian University of Technology(Grant No.DUTIO-ZG-202307)the Key Project of DUT for International Students Studying and Researching in China:Innovation and Practice of Talent Cultivation Model in the Field of Smart Buildings for the“Belt and Road”Initiative(Grant No.1103-82120001).
文摘Sensors are a crucial component in heating,ventilation,and air conditioning(HVAC)control systems,and the quality of them plays an important role in control accuracy.In the research of fault detection and control optimization,improving sensor data quality has inspiring potential in application.It has been largely limited to the application of signal processing methods in research focus,whereas a detailed analysis of the characteristics of signals from various sensors of the HVAC system has not been conducted.Therefore,this study analyzes the time-frequency domain characteristics of control sensors within HVAC systems through integrating the structural design and control logic of such systems.Additionally,the research examines the correlations between control sensors in HVAC systems.Based on statistical principles and the energy-mass dynamic laws of the equipment,this paper defines first-class(Ⅰ)correlated sensors and second-class(Ⅱ)correlated sensors.To sum up,the main contribution of this paper is conducting a fundamental study on the characteristics of control sensors within HVAC systems,providing theoretical reference for future research on HVAC system fault diagnosis and control optimization.
基金supported by Natural Science Foundation of China under Grant Nos.60821091 and 60736022
文摘The capability of ADRC is studied for linear time-invariant SISO minimum-phase systems with unknown orders, uncertain relative degrees, and unknown input disturbances. It is proved that ADRC can reject the unknown input disturbance and guarantee the close-loop stability for the plants with unknown but bounded relative degrees. Meanwhile, some close-loop performances can be achieved. The influence of the sensor noise is also discussed. And it is demonstrated by numerical examples that one ADRC with fixed parameters can be applied to a group of plants of different orders, relative degrees, and parameters.
